package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.hmdp.dto.Result;
import com.hmdp.dto.ScrollResult;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.RedisConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Set;
import java.util.stream.Collectors;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {

    @Resource
    IUserService userService;
    @Resource
    StringRedisTemplate stringRedisTemplate;

    @Resource
    IFollowService followService;
    @Override
    public Result likeBlog(Long id) {
        //1 获取用户id
        Long userId = UserHolder.getUser().getId();
        //2 判断用户是否已点赞
        String key = RedisConstants.BLOG_LIKED_KEY + id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if(score == null){
            //3 未点赞
            //3.1 数据库点赞加1
            boolean isSuccess = update().setSql("liked = liked + 1").eq("id", id).update();
            //3.2 将用户添加到点赞集合
            if(isSuccess){
                stringRedisTemplate.opsForZSet().add(key, userId.toString(), System.currentTimeMillis());
            }
        }else{
            //4已点赞
            //4.1 数据库点赞减1
            boolean isSuccess = update().setSql("liked = liked - 1").eq("id", id).update();
            //4.2 将用户移除点赞集合
            if(isSuccess){
                stringRedisTemplate.opsForZSet().remove(key, userId.toString());
            }
        }

        return Result.ok();
    }

    @Override
        public Result queryBlogLikes(Long id) {
            //1 查询点赞top5的用户 zrange 0 4
            String key  = RedisConstants.BLOG_LIKED_KEY + id;
            Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
            if(top5 == null || top5.isEmpty()){
                return Result.ok(Collections.emptyList());
            }
            //2 解析用户id
            List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
            String idsStr = StrUtil.join(",", ids);
            //3 转化成用户对象  where id in (idsStr) order by field(id, idsStr)
            List<UserDTO> userDTOS = userService.query().in("id", ids)
                    .last("order by field(id,"+ idsStr +")").list()
                    .stream()
                    .map(user -> BeanUtil.copyProperties(user, UserDTO.class))
                    .collect(Collectors.toList());
            //4 返回
            return Result.ok(userDTOS);
        }

    @Override
    public Result saveBlog(Blog blog) {
        //1 获取登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        //2 保存探店博文
        save(blog);
        //3获取粉丝id
        List<Follow> follows = followService.query().eq("follow_user_id", blog.getUserId()).list();

        //4 推送消息给粉丝
        for(Follow follow : follows){
            Long userId = follow.getUserId();
            String key = "feed:" + userId;
            stringRedisTemplate.opsForZSet().add(key, blog.getId().toString(), System.currentTimeMillis());
        }
        // 返回id
        return Result.ok(blog.getId());
    }

    @Override
    public Result queryBLogOfFollow(Long max, Integer offset) {
        //1 获取登录id
        Long userId = UserHolder.getUser().getId();
        //2 查询收件箱
        String key = RedisConstants.FEED_KEY + userId;
        Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.opsForZSet()
                .reverseRangeByScoreWithScores(key, 0, max, offset, 2);
        // 非空校验
        if(typedTuples == null || typedTuples.isEmpty()){
            return Result.ok();
        }
        //3 解析数据 blogId 时间戳 offset
        List<Long> ids = new ArrayList<>();
        long minTime = 0;
        int os = 1;
        for(ZSetOperations.TypedTuple<String> tuple : typedTuples){
            ids.add(Long.valueOf(tuple.getValue()));
            long time = tuple.getScore().longValue();
            if(time == minTime){
                os++;
            }else{
                minTime = time;
                os = 1;
            }
        }
        //4 封装blog
        String idsStr = StrUtil.join(",", ids);
        List<Blog> blogs = query().in("id", ids).last("order by field(id, " + idsStr + ")").list();
        for(Blog blog : blogs){
            queryBlogByUserId(blog);
            isBlogLiked(blog);
        }
        //5 封装ScrollResult
        ScrollResult r = new ScrollResult();
        r.setList(blogs);
        r.setMinTime(minTime);
        r.setOffset(os);
        return Result.ok(r);
    }
    private void queryBlogByUserId(Blog blog) {
        Long userId = blog.getUserId();
        User user = userService.getById(userId);
        blog.setName(user.getNickName());
        blog.setIcon(user.getIcon());
    }

    private void isBlogLiked(Blog blog) {
        //1 获取用户id
        UserDTO user = UserHolder.getUser();
        if(user == null){
            return;
        }
        Long userId = user.getId();
        //2 判断用户是否已点赞
        String key = RedisConstants.BLOG_LIKED_KEY + blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if(score != null){
            blog.setIsLike(true);
        }else {
            blog.setIsLike(false);
        }
    }
}
